Sulphydryl Groups Research Articles

Microbe-mediated synthesis of defect-rich CeO2 nanoparticles with oxidase-like activity for colorimetric detection of L-penicillamine and glutathione.

To enhance production efficiency, curtail costs, and minimize environmental impact, developing simple and sustainable nanozyme synthesis methods has been the focus of relevant research. In this report, graphite-coated CeO2 nanoparticles (CeO2 NPs) with multiple defects (Ce3+ defects, oxygen vacancies and carbon defects) were synthesized via the culture filtrate of the extremely radioresistant bacterium Deinococcus wulumuqiensis R12 (D. wulumuqiensis R12). The as-prepared CeO2 NPs exhibit remarkable oxidase (OXD)-like activity, efficiently catalyzing the oxidation of the chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) to form oxTMB, even in the absence of H2O2. The electron-rich bioactive substances in the supernatant were demonstrated to modulate the electronic state of the Ce atom and played a key role in the formation of multiple defects, thereby enhancing the OXD-like activity of CeO2 NPs. Based on the inhibitory effect of sulphydryl groups (-SH) on the TMB-CeO2 system, a colorimetric strategy for the detection of both L-penicillamine (L-PA) and glutathione (GSH) was devised and successfully applied in real sample analysis. The linear ranges of L-PA and GSH detection were found to be 10-500 μM and 9-200 μM with the limits of detection (LODs) at 8.53 and 5.19 μM, respectively. This work provides a straightforward, eco-friendly and nontoxic method for the synthesis and defect construction of CeO2 NPs with OXD-like activity.

Influence of the Maillard reaction on the structure of β-casein using a simulated cooking system

Abstract Glycation during food processing can change the structural characteristics of dietary protein and endow a variety of functionalities. Milk β-casein (MC) with five different types of carbohydrates (i.e., glucose, sucrose, amylose, amylopectin, and soluble starch) in a simulated cooking system at 98 and 115 °C was investigated. The changes in ultraviolet absorption, endogenous fluorescence intensity, surface hydrophobicity, particle size, free amino group, free sulphydryl group, and circular dichroism were measured. For the glucose-added group, the lowest free amino content and most significant spectral changes among all groups were observed after heating at 115 °C for 6 hr (OH-MC-Glu). Results showed that glycation activities of five sugars were glucose > sucrose > soluble starch> amylopectin ≈ amylose. Under the simulated cooking system, the secondary structure and conformation of glycated MC changed to different degrees, which were affected by the glycation degree. Moderate glycation (0–2 hr of heating) may promote the conversion reaction of sulfhydryl-disulfide bond (SH-SS) in MC, causing cross-linking and self-aggregation of MC, and induce the particle size increase of MC. Excessive glycation (2–6 hr of heating) can further reduce the surface hydrophobicity of MC, inhibit self-aggregation of MC, and reduce the particle size of MC.

Cysteine‐Based Dynamic Self‐Assembly and Their Importance in the Origins of Life

AbstractThe knowledge regarding the origins of life from inanimate materials is still elusive. It was proposed that biological building blocks evolved from the inorganic substances present in the early earth conditions. However, the process by which chemistry can be converted into biology has not yet been achieved in the laboratory. The artificial system in the out‐of‐equilibrium state must maintain a few critical features of life, like compartmentalization, metabolism, and replication, to be considered alive. In this direction, working with cysteine (Cys)‐based molecules is strategic to understand the life evolution process. The presence of the sulphydryl (−SH) group in the Cys‐residue can build a dynamic equilibrium state through disulfide redox chemistry under the proper guidance of oxidizing and reducing agents. In this review article, our primary focus is to discuss the Cys‐containing short‐peptide‐based self‐assembly and disassembly processes. The formation of disulfide bonds sometimes helps in the self‐assembly process and gelation, but the reverse is also true in some cases. In the later part of this article, we cover the fact that these sulphydryl‐based systems have shown their adaptability to mimic different life‐essential criteria to participate in Darwinian evolution.

Effects of thermal treatment on the physicochemical and structural properties of wheat gluten proteins: insights from gluten, glutenin, and gliadin fractions

SummaryThis study examined changes in heat‐induced gluten proteins, focusing on their structure, physicochemical properties, and molecular analysis. The results demonstrated that gliadin had a high denaturation temperature (68.04 °C) and minimal aggregation during heating (25 °C–95 °C), yet it hindered thermal reaction progress of gluten effectively. Heating caused a shift from α‐helical structure to random coil and β‐turn structures, with a decrease in fluorescence intensity. High temperature reduced sulphydryl groups in gluten and glutenin, reaching 0.64 and 0.58 mmol L−1, respectively. However, the content of sulphydryl groups in gliadin remained relatively stable at around 0.37 mmol L−1. Notably, the configuration of disulphide bonds in gliadin, particularly in the g‐g‐g configuration, displayed greater stability. Microstructure analysis revealed increased compactness in all protein fractions as temperature rose. Overall, gliadin had greater thermal stability, impeding glutenin aggregation and gluten network formation. These findings provide valuable insights for cooking, processing, and storage of gluten proteins.

Recognizing adsorption of aqueous Cr(VI), As(III), Cd(II), and Pb(II) ions by amino groups hollow polymer adsorbent

Recognizing adsorption of aqueous Cr(VI), As(III), Cd(II), and Pb(II) ions by amino groups hollow polymer adsorbent

Effects of Gnaphalium affine extract (GAE) and sodium pyrophosphate (PP) on •OH‐induced oxidation and the structure of myofibrillar proteins

SummaryThis study investigated the effects of the combination of Gaphalium affine extract (GAE) and sodium pyrophosphate (PP) on the structure and oxidative stability of porcine myofibrillar proteins (MPs) under oxidative stress. The results showed that GAE was rich in total flavonoids and total phenols (37.09% and 67.50%, respectively). GAE had strong free radical scavenging ability, especially for •OH, and the semi‐inhibitory concentration (IC50) of •OH reached as high as 3.59 μg/mL, which was slightly lower than that of the standard antioxidant vitamin C (Vc). The addition of GAE and PP significantly inhibited the formation of carbonyl groups compared to the control group (P < 0.05). The presence of GAE further promoted the loss of total sulphydryl groups by 3.52% compared to the oxidative control group (P < 0.05). However, PP and PP+G significantly inhibited the loss of total sulphydryl groups (P < 0.05). The further reduction in the carbonyl content, increase in the hydrogen bond content, inhibition of the conversion of sulphydryl groups to disulphide bonds, and decrease in the cross‐linking aggregation of corresponding proteins all indicate that GAE and PP could cooperatively regulate the oxidation of MPs. An appropriate amount of PP effectively modified the damage caused by GAE on both the secondary and tertiary structure of MPs to maintain their structural stability, however, a relatively higher concentration of PP led to a substantial degree of MP collapse and affected the quality of the proteins. These results suggest that the oxidative stability of MPs can be improved by the addition of an appropriate amount of GAE (0.2 mg/g protein) combined with PP (1 mM).

A tri-responsive dual-drug delivery system based on mesoporous silica nanoparticles@polydopamine@graphene oxide nanosheets for chemo-photothermal therapy of osteosarcoma

A tri-responsive dual-drug delivery system based on mesoporous silica nanoparticles@polydopamine@graphene oxide nanosheets for chemo-photothermal therapy of osteosarcoma

Effects of CaCl2 concentration on fibrils formation and characteristics of soybean protein isolate and β-conglycinin/glycinin

Effects of CaCl2 concentration on fibrils formation and characteristics of soybean protein isolate and β-conglycinin/glycinin

Structural characterization and functional properties of egg white protein treated by electron beam irradiation

Structural characterization and functional properties of egg white protein treated by electron beam irradiation

Effects of innovative gelation and modified tapioca starches on the physicochemical properties of surimi gel during frozen storage

SummaryThis study presented a comparative evaluation of the effects of 5% tapioca starch, acetylated distarch phosphate and hydroxypropyl distarch phosphate (HPDSP) on the changes in surimi gel quality after the traditional gelation procedure (suwari‐cooking‐freezing) and a novel gelation procedure (suwari‐freezing‐cooking, SFC). Overall, subjected to the SFC procedure, lower hydrophobic interactions, lower total sulphydryl group content, higher disulphide bond content and a more orderly protein conformation was observed in the HPDSP‐surimi gel. These changes resulted in smaller drip loss, stabler breaking force and deformation, and less structural damage during frozen storage. Since the strongest hydrophilicity of HPDSP and the lowest gelatinisation temperature (63.15 °C), when it was reheated and then gelatinized, it interacted more closely with the protein. These findings indicated that subjected to the SFC procedure, the addition of 5% HPDSP effectively decreased the changes in the quality of the surimi gel.

Improvements of dried noodles qualities using two-stage resting: Explanation from macro and micro perspectives.

The purpose of this study was to elucidate the effects of two-stage resting (dough crumbs and dough sheets resting) on the quality of dried noodles. An improvement mechanism was explored according to the texture of dough sheets, gluten network, and microstructure of cooked noodles. After two-stage resting, the extensibility of dough sheets, the contents of glutenin macro polymer (GMP), and disulfide bonds (S-S) increased significantly (p < .05), whereas the content of sulphydryl group (-SH) significantly declined. From the perspective of microstructure, the average length and width of dough sheets protein experienced a significant reduction (p < .05); however, the branching rate, the number of protein lines, and the total length of the protein lines significantly increased (p < .05). Furthermore, the average network line length and width of cooked noodles were significantly reduced as the branching rate rose (p < .05); meanwhile, the number of holes significantly increased while the average area significantly decreased (p < .05). Overall, the two-stage resting has improved the quality of dried noodles and contributed to a more uniform and compact gluten network distribution.

Ovalbumin and Kappa-Carrageenan Mixture Suppresses the Oxidative and Structural Changes in the Myofibrillar Proteins of Grass Carp (Ctenopharyngodon idella) during Frozen Storage.

This study was done to analyze the cryoprotective influence of ovalbumin (OVA) with kappa-carrageenan (KC) in grass carp myofibrillar proteins during frozen storage. Ca2+-ATPase activity of MP was significantly reduced due to protein denaturation and showed a direct association with decreased sulphydryl (SH) contents and tertiary structural properties. Besides that, an increase in carbonyl, surface hydrophobicity, and dityrosine contents was observed. The addition of OVA-KC significantly restricted the decline in Ca2+-ATPase and SH groups, which were further confirmed by the retarded increase in carbonyls. Furthermore, the addition of OVA-KC increased the stability of α-helix contents. Moreover, MP treated with 6% OVA-KC also improved intermolecular interaction forces linked with gelling and water holding properties of MP. Therefore, it can be concluded that OVA-KC could be used as an effective cryoprotectant in fish and related products for preservation and commercialization.

Optimization of High Hydrostatic Pressure Treatments on Soybean Protein Isolate to Improve Its Functionality and Evaluation of Its Application in Yogurt.

This work aimed to improve the functional properties of soybean protein isolate (SPI) by high hydrostatic pressure (HHP) and develop SPI incorporated yogurt. Response surface methodology (RSM) was used to optimize the HHP treatment parameters, including pressure, holding time, and the ratio of SPI/water. Water holding capacity, emulsifying activity index, solubility, and hardness of SPI gels were evaluated as response variables. The optimized HPP treatment conditions were 281 MPa of pressure, 18.92 min of holding time, and 1:8.33 of SPI/water ratio. Water and oil holding capacity, emulsifying activity, and stability of SPI at different pH were improved. Additionally, relative lipoxygenase (LOX) activity of HHP treated SPI (HHP-SPI) was decreased 67.55 ± 5.73%, but sulphydryl group content of HHP-SPI was increased 12.77%, respectively. When incorporating 8% of SPI and HHP-SPI into yogurt, the water holding capacity and rheological properties of yogurt were improved in comparison with yogurt made of milk powders. Moreover, HHP-SPI incorporated yogurt appeared better color and flavor.

Factorial Analysis of the Cardiometabolic Risk Influence on Redox Status Components in Adult Population.

Different byproducts of oxidative stress do not always lead to the same conclusion regarding its relationship with cardiometabolic risk, since controversial results are reported so far. The aim of the current study was to examine prooxidant determinant ((prooxidant-antioxidant balance (PAB)) and the marker of antioxidant defence capacity (total sulphydryl groups (tSHG)), as well as their ratio (PAB/tSHG) in relation to different cardiometabolic risk factors in the cohort of adult population. Additionally, we aimed to examine the joint effect of various cardiometabolic parameters on these markers, since to our knowledge, there are no studies that investigated that issue. A total of 292 participants underwent anthropometric measurements and venipuncture procedure for cardiometabolic risk factors assessment. Waist-to-height ratio (WHtR), body mass index, visceral adiposity index (VAI), and lipid accumulation product (LAP) were calculated. Principal component analysis (PCA) grouped various cardiometabolic risk parameters into different factors. This analysis was used in the subsequent binary logistic regression analysis to estimate the predictive potency of the factors towards the highest PAB and tSHG values. Our results show that triglycerides, VAI, and LAP were positively and high density lipoprotein cholesterol (HDL-c) were negatively correlated with tSHG levels and vice versa with PAB/tSHG index, respectively. On the contrary, there were no independent correlations between each cardiometabolic risk factor and PAB. PCA revealed that obesity-renal function-related factor (i.e., higher WHtR, but lower urea and creatinine) predicts both high PAB (OR = 1.617, 95% CI (1.204-2.171), P < 0.01) and low tSHG values (OR = 0.443, 95% CI (0.317-0.618), P < 0.001), while obesity-dyslipidemia-related factor (i.e., lower HDL-c and higher triglycerides, VAI, and LAP) predicts high tSHG values (OR = 2.433, 95% CI (1.660-3.566), P < 0.001). In conclusion, unfavorable cardiometabolic profile was associated with higher tSHG values. Further studies are needed to examine whether increased antioxidative capacity might be regarded as a compensatory mechanism due to free radicals' harmful effects.

The effect of a variable initial pH on the structure and rheological properties of whey protein and monosaccharide gelation via the Maillard reaction

The effect of a variable initial pH on the structure and rheological properties of whey protein and monosaccharide gelation via the Maillard reaction

Crocetin attenuates the oxidative stress, inflammation and apoptosis in arsenic trioxide-induced nephrotoxic rats: Implication of PI3K/AKT pathway

Crocetin attenuates the oxidative stress, inflammation and apoptosis in arsenic trioxide-induced nephrotoxic rats: Implication of PI3K/AKT pathway

CORONAVIRUS AND ITS MAIN PROTEASE: AN INSIGHT FOR DRUGS DESIGN BY MOLECULAR DOCKING

Many virus need their sulphydryl groups to be reduced in order to be allowed to enter cells. SARS-CoV-2, which belongs to Coronaviridae family and is responsible for coronavirus disease 2019 or COVID-19, has cysteine-rich proteins in its capsid as the main CoV protease (MPRO), which must be intact and active maintaining the viral activity. Considering that MPRO is an important molecular target for development of antiviral drugs, this work motivation was the structural study of the possible ways of interaction between drugs and viral cysteines by molecular docking technique for design of new potential inhibitors of MPRO and its virulence.

Plant Extracts and Isolated Compounds Reduce Parameters of Oxidative Stress Induced by Heavy Metals: An up-to-Date Review on Animal Studies.

Heavy metals are elements that are naturally found in the earth. They are used in many modern-day applications in agriculture, medicine, and industry. Heavy metal poisoning occurs when the body's soft tissues absorb too much of a particular metal. The heavy metals of interest for this review paper were cadmium, arsenic, mercury, and lead since these are the most common metals that the human body can absorb in toxic amounts. Different plant species were investigated in recent years for their effect on oxidative stress parameters after intoxication with heavy metals. This review paper is focused on the current update to research on heavy metals induced oxidative stress in animal models and improvement of the oxidative stress parameters upon/co-/after treatment with different plant extracts and isolated compounds. The available literature was screened for the novel data regarding the influence of plant extracts and compounds on heavy metals induced oxidative stress. For that purposes Scopus database was used, looking for the publications in the last 5-10 years with the key terms: plant extracts, oxidative stress, in vivo, cadmium, lead, mercury and arcenic. Various parameters of oxidative stress were investigated, and their improvement with plant extracts/ compounds was observed in the brain, lungs, kidneys, liver, uterus, testis, thymus, spleen, heart, skin and blood of experimental animals. Common parameters used to determine oxidative stress in animals were: superoxide dismutase; catalase; reduced glutathione; glutathione reductase; glutathione-S-transferase; glutathione peroxidase; lipid peroxidation; oxidized glutathione; malondialdehyde; xanthine oxidase; nonprotein-soluble thiol; thioredoxin reductase; total sulphydryl group; nitric oxide; γ-glutamyl cysteine synthetase. The most investigated species for antioxidant effects upon intoxication with heavy metals seem to be Allium sp., Bacopa monniera, Camellia sinensis, Moringa oleifera, Vitis vinifera and Zingiber officinale. According to literature data, the most promising effect to alleviate symptoms of intoxication was achieved with proanthocyanidins obtained from Vitis vinifera.

Changes in oxidative stress markers in plasma of sows during periparturient period.

The aim of the present study was to determine changes in oxidative status in plasma of sows during periparturient period using markers of lipid and protein peroxidation intensity. Plasma from 12 pregnant gilts collected on days 14 and 1 before parturition and on days 1, 7 and 14 postpartum was used in the study. As indicators of alterations in the oxidative status, plasma concentrations of thiobarbituric acid reactive substances (TBARS) and sulphydryl groups (SH groups) were measured spectrophotometrically, as well as plasma concentrations of bityrosine and formylokinurenine were determined by the spectrofluorimetric method. Com-pared to the 14th day antepartum, the concentration of TBARS increased significantly on day 1 postpartum and then decreased significantly on days 7 and 14 after parturition. The concentration of SH groups increased significantly on the last day before parturition and decreased significantly on day 14 postpartum. The concentration of bityrosine increased significantly on the last day before parturition and decreased significantly on days 7 and 14 postpartum. The concentration of formylokinurenine increased significantly on the last day before parturition, remained at this level on the first day after parturition and then decreased slightly on days 7 and 14 postpartum. These results indicate that during periparturient period in sows, especially around the parturition, the oxidative/antioxidative balance is disturbed, which leads to oxidative stress. Considering that oxidative stress is potentially harmful for mothers and neonates, this may be an important factor in the increased risk of diseases occurring during this period.

Effects of the enzymatic hydrolysis treatment on functional and antioxidant properties of quinoa protein acid-induced gels

Effects of the enzymatic hydrolysis treatment on functional and antioxidant properties of quinoa protein acid-induced gels